Yttrium oxide along with CaO, MgO and BN are considered as
candidate materials for insulator coating. Particularly due to its
extremely high temperature stability - up to approx. 2,200°C - and
its outstanding resistance to alkaline melts with high oxygen
affinity, Y2O3 is used in numerous special applications such as in
insulators, glass, electrical conducting ceramics, refractories,
and stains.
Phosphors
Yttria is widely used to make Eu:YVO4 and Eu:Y2O3 phosphors that
give the red color in color TV picture tubes.
Yttria lasers
Y2O3 is a prospective solid-state laser material. In particular,
lasers with ytterbium as dopant allow the efficient operation both
in continuous operation and in pulsed regimes.At high concentration
of excitations (of order of 1%) and poor cooling, the quenching of
emission at laser frequency and avalanche broadband emission takes
place.(Yttria-based lasers are not to be confused with YAG lasers
using yttrium aluminum garnet, a widely used crystal host for rare
earth laser dopants).
Gas Lighting
The original use of the mineral yttria and the purpose of its
extraction from mineral sources was as part of the process of
making gas mantles and other products for turning the flames of
artificially-produced gases (initially hydrogen, later coal gas,
paraffin, or other products) into human-visible light. This use is
almost obsolete - thorium and cerium oxides are larger components
of such products these days.
Dental ceramics
Yttrium oxide is used to stabilize the Zirconia in late-generation
porcelain-free metal-free dental ceramics. This is a very hard
ceramic used as a strong base material in some full ceramic
restorations.[8] The zirconia used in dentistry is zirconium oxide
which has been stabilized with the addition of yttrium oxide. The
full name of zirconia used in dentistry is "yttria-stabilized
zirconia" or YSZ.
Microwave filters
Yttrium oxide is also used to make yttrium iron garnets, which are
very effective microwave filters.
Superconductors
Y2O3 is used to make the high temperature superconductor YBa2Cu3O7,
known as "1-2-3" to indicate the ratio of the metal constituents:
2 Y2O3 + 8 BaO + 12 CuO + O2 → 4 YBa2Cu3O7
This synthesis is typically conducted at 800 °C.
Inorganic synthesis
Yttrium oxide is an important starting point for inorganic
compounds. For organometallic chemistry it is converted to YCl3 in
a reaction with concentrated hydrochloric acid and ammonium
chloride.
